x = int(input())
if x >= 30:
    print('Yes')
elif x < 30:
    print('No') x = int(input()) x int(input()) int input() input if x >= 30:
    print('Yes')
elif x < 30:
    print('No') x >= 30 x 30 print('Yes') print 'Yes' elif x < 30:
    print('No') x < 30 x 30 print('No') print 'No' x = int(input()) int(input()) x
x = int(input())
if x >= 30:
    print('Yes')
elif x < 30:
    print('No')